D.C generator. Part – 1

1. In a D.C. generator the critical resistance refers to the resistance of

A. Brushes

B. Field

C. Armature

D. Load

2. In D.C. generator, lap winding is used for

A. Low voltage, high current

B. High voltage, high current

C. High voltage, low current

D. Low voltage, low current

3. The principle of dynamically induced e.m.f. Is utilized in a

A. Choke

B. Motor

C. Battery

D. Generator

4. The interpoles of a DC machine are normally connected,

A. In series with the load

B. In parallel with the load

C. In series with the shunt field coil

D. None of the above

5. In DC generators the polarity of the interpoles

A. is opposite to that of the main pole ahead

B. is the same as that of the main pole ahead

C. is neutral as these poles do not play part in generating e.m.f.

D. is the same as that of the immediately preceding pole

6. The dummy coil in d.c. Machine are useful to

A. Increase the efficiency

B. Improve the commutation

C. Reduce the cost of machine

D. Maintain the mechanical balance of armature

7. The EMF induced in conductor rotating in bipolar field is

A. D.C.

B. A.C.

C. A.C. or D.C. both

D. None of the above

8. The _____ generator has poorest voltage regulation.

A. Shunt

B. Over compound

C. Under compound

D. Differential compound

9. Which of the following tests can be conducted on other than shunt machines?

A. Swinburne test

B. Field test

C. Retardation test

D. Back to back test

10. The dc generator works on the principle of

A. Fleming’s left hand rule

B. Fleming’s right hand rule

C. Lenz’s law

D. None of these